pass parturition events on to next app

[sarahcd]

See the Road Intersections App for an example that does this. We'll discuss a general purpose solution with Andrea.

[sarahcd]

I think this one is done, just not fully documented yet. Here are attributes I think are passed on in the MoveStack, guessing the definitions based on the output:
distance: distance traveled from this event to subsequent event (meters)?
timediff: difference in time from this event to the subsequent event (hours)?
nsd: net squared displacement from that of the first location in the track segment (km)?
speed: speed of travel from this event to subsequent event (meters/second)?
rollm: rolling average speed over ??? (meters/second)?
cnd: ?
run: ?
run.positive: record count in the current run meeting threshold conditions? (But see below, the last row has run.positive=0 and case=1)
crun: ?
case: 1 = part of parturition event, 0 = not part of parturition event

Here are values from the data of one event. I'm not sure if the last record is included in the event.